Nine US marines have been killed and nine injured in what is thought to be a bomb attack near the Iraqi city of Falluja, the US military has said.

In a statement, the officials said the deaths occurred in the western Anbar province on Saturday.

The rebel-held city of Falluja is being threatened with a major military strike by US and Iraqi forces.

The interim Iraqi government is continuing peace talks with Falluja representatives this weekend.

The soldiers, from the 1st Marine Expeditionary Force, were killed while carrying out what US military officials called "increased security operations" in the province, which also includes the insurgent stronghold of Ramadi.

Eight were initially reported to have been killed, but the army issued a new death toll of nine on Sunday.

The casualty figures are the highest for the US in a single attack in more than six months.

Details of the incident remain sketchy.

Final chance

US forces have been carrying out a heavy bombardment of Falluja in preparation for a full-scale attack.

They say the Sunni-dominated city has become a safe haven for rebels linked to Jordanian rebel Abu Musab al-Zarqawi.